Aminoalkyl derivatives of thiophene



Patented Sept. 30, 1952 AMINOALKYL DERIVATIVES THIOPHENE Howard D. Hartough, Pitman, and Sigmund J.

Lukasiewicz, Woodbury, N. J assignors to Socony-Vacuum Oil Company, Incorporated, a corporation of New York No Drawing. Application January 3, 1951,

Serial No. 204,264

6 Claims.

1 I The present invention relates to the condensation of thiophene and thiophene derivatives with formaldehyde and its polymers and ammonia and Blicke and Burckhalter synthesized z-thenyl amine by treating Z-(bromomethyl)-thiophene with hexamethylenetetramine (J. A. C. S. 64, 477

(1942)). The product of this primary reaction was then treated with hydrochloric acid in the presence of ethyl alcohol to obtain 2-thenyl amine hydrochloride. The free amine had a boiling point of 73-75 degrees centigrade at 11 millimeters of mercury 195-200 C. at 760 millimeters of mercury). Putokhin and Egonova obtained 2-thenyl amine in yields of 50-55 per cent by re ducing 2-thenyl oxime (CAI-I3SCH=NOH) with zinc dust and hydrochloric acid [J Gen. Chem. (U. S. S. R.) 10, 2873 (1940)]. They reported that the free amine possessed the following physical properties: boiling point at 26 millimeters of mercury88 degrees centigrade (195 C. at 760 millimeters of mercury), D4 =1.1370 and refractive index, n =l.5678.

It has now been found that Z-thenyl amine, di-(Z-thenyl) amine and polymeric amines can be produced by the condensation of thiophene with ammonium halide by means of a highly reactive aldehyde such as formaldehyde. The following equation generalizes the reaction:

HC-CH II H g H CH CHIO NH4X 6585 C.

aqueous portion of the reaction mixture and thus are readily separated from the unreactedthiophenes. When polymeric formaldehyde is employed the water of reaction is sufficient to effect h'yde or trioxane.

C-CHQNHzHX formaldehyde.

solution of the hydrohalides of amines I, II and III. Amines I, II and III can be separated as the free bases by the addition of caustic. III can be separated by weaker basic materials such assodium acetate.

The free amines can be obtained from the hydrohalides by standard procedures, for example, by treatment of the hydrochloride with aqueous caustic followed by extraction with benzene from a saturated salt solution. Amine I and amine II have been isolatedin the pure'state by distillation in vacuum. Amine III thermally polymerizes when heated to temperatures exceeding 200-210 degrees ,centigrade.

It is to be noted that analyses of amine III and the chemicalproperties thereof indicate that it is a polymeric amine containing several units of the C4H3S.CH2 type. It is not a tri-(2- thenyl) amine because the sulfur content is too low while the nitrogen content and the molecular Weight are too high for the trithenyl amine.

Amines I and II, i. e., Z-thenyl amine and di-2- thenyl amine, respectively, are strongly basic, form addition complexes with carbon dioxide on contact with air and dissolve rubber on contact. They may be distilled to a water-white product but soon show a yellow discoloration.

Amine III (the polymeric amine) is a weakly basic amine that can be freed of its hydrochloride by neutralization with sodium acetate. Amines I and II cannot be so freed. This characteristic indicates that amine III contains tertiary amine groupings.

The formaldehyde to be used in this reaction may be in the form of an aqueous solution such as the conventional aqueous solution containing 36-40 per cent formaldehyde, known commercially as Formalin, or in the form of paraformalde- When polymeric forms of formaldehyde are used, it has been found advantageous to add a small amount, say a few III milliliters of water or of an acid per mole of The acid to be used in one with a dissociation constant of about 10- or less, such as acetic acid.

Hexamethylenetetramine when mixed with thiophene and hydrochloric acid slowly added gives rise to the same reaction and the same prod- Amine may be substituted for formaldehyde and ammonium chloride.

Accordingly, it is an object of this invention to provide a method for producing 2-thenyl amine and di-2-thenyl amine. It is another object of the present invention to provide a method for producing derivatives of 2-theny1 amine and di- 2-theny1 amine. present invention to provide a method for pro-v ducing sub-resinous and resinous bodies from thiophene and compounds containing the thicphene nucleus having stable electropositive .sub.. stituents other than hydroxyl [(OH'lil ior amino [(NHzH groups attached to the thiophene nucleus, formaldehyde or its polymers .and .ammonium halides other than the fluoride. objects and advantages will become apparent from the following description.

Before proceeding withQa general discussion of Other It is a further object of the to enter into further combination forming compounds of the second order. Thus, for example, sodium oxide, formed by the union of sodium and oxygen, is a compound of the first order possessing free positive electricity, while S03, formed from sulfur and oxygen, is a compound belonging to the same order but possessing free negativeelectricity. It iSeObViOllS thatthese compoundslmay in turn combine, by virtue of their opposite polarities, to form sodium sulfate.

.A similar interpretation can be applied to .benzene chemistry. Although theactual terms electropositive 'substituents and electro-negati-ve'substituents are not found therein, Paul D.

:Bartlett shows .in 'Gilman, Organic Chemistry,

John' Wiley and Son, N. Y. 0., 2nd edition, vol. I,

. 1943, pp. *208-209, in a discussion of the orientathe apresentinvention :it "appears desirable to .dis-

cuss the significance of {the term stable electropositive .substituents. In normal substitution reactions-in the thiophene series such as aminomethylation and acylationone :is onlyzconcerned with the groups that normallyzorientatozthe orthoand para-positions :inthe benzene series since it has been found that groups whichare typically meta-directing .in the benzene series inactivate the thiophene nucleus :so that these :two reactions-fail to take place. .Also; it has been recognized'that the substitution .rules valid-for ben-- zene chemistry do not apply $0 .thiophene rchemistry. The sulfur atom in the thiophen'e nucleus exerts an, orientation 'efiect on entering substituents, while, in benzene, substitution risrrandom, all positions ebeing equivalent. The directive influence or zori'entationsfactors .of benzene result onl yifroma substituent group on the benzene nucleus. 0n the :other hand; any substituent on the thi'ophene nucleus is .either additive to or in competition "with the :directive influences .already within the thiophene nucleus. Thus, a typical rheta-directing group for members .of the benzene series may .have 'little or no directional influence onany entering substituent for members of the thiophene :series. Therefore, it 'is necessary to examine these substituents as-to their electronic or electrophilic nature to :devise a classification based upon very elementary-concepts forthepurpQSe of distinguishing between those derivatives -of thiophene which will participate in the concerned reaction to provide satisfactory results as those which are not concerned herewith.

The term, electropositive substituents, was chosen'to designate, in "the thiophene series,

' groups that are normally considered in the bencharges in these compounds are not necessarily neutralized, there might'rema'in a surplus of 'positi-veor negative charges which would enable't'hem tion in .chlorobenzene, an excellent interpretation of this tendency for one group to furnish electrons to the aromatic group, producing thereby a negative charge on the benzene nucleus thus making the substituentlgroup positively charged or :a felectropositive :substituent by sharing its electronswith zthezaromatic nucleus. Thus, other groupszgiven by .Gi-lman', p ge .203, in 'Table II of theflrtho-para-type will :also furnish electrons to the-benzene nucleus. I These canzalso :becla-ssifled T as electropositive :substituent groups.

.Karrer, Organic aChemistry, :Elsevier (1947)., ppL 4D5 tand406,tmakes1this statement When :newpsubstituents are introduced :into an already substituted benzene nucleus, they .cannot, :as :a rule, enter any desired position. The positions they "take up .are affected by .the groups already present; "these direct the iincoming groups .'.to definite positions. Two classes of substituents :may be 'difi'erentiated, .those which direct an incoming substituent chiefly into "the orth'oand para-positions, :and .those which are meta cdirectin'g. To .the first class rbelong Cl, Br, I, CHsCn-Hznn, 0H, NHz; and to the second class OH, and .NH2 and that stable electropositive" substituentsare 'Cl,Br,.I, CI-Ia,.and CnHZn-l-l thereby excluding groups such as .NI-Iz and --OH wherein the parent compounds are known to be highly unstable. Consequently, the term, stable electropositive substituent groups, as used herein includes in part -OR, R (where R is an alkyl group), C1, -Br, --.I, CsH5,

-'-CH2COOI-I, --NHCOCH3,

CH2CN, CH=CHCOOH, CH=CHCOOR (where Ris alkyl'or aryl) CECCOOR (where R. is alkyl or aryl) and ,CH2X (where X is Cl, Br or I).

For general interest in this connection, electronegative substituents, i.

drawing electrons from the benzene nucleus or any aromatic nucleus having resonance such as thiophene. Typical examples are the NO2, -SO3H, -COCH3, -'COOI-I and -CH0 groups.

7 e., meta-directinggroupsin the benzene-series, are the groups withdependent upon the conditions under which the I reaction takes place.

When ammonium halide, formaldehyde and of ammonium halide is used whether -the thiophene or the formaldehyde be in excess and that an increase in the amount of sub-resinous body appears to be correlated with the disappearance of a proportionate amount of secondary amine.

The data in Table 11 show that the fundamental reaction takes place in a ratio of reactants of about 0.5 mole of thiophene for 1 mole of formaldehyde and 0.5 mole of ammonium halide, i. e., a mole ratio of 1:2:1.

TABLE II Moles of Reactants Utiliied V v Moles of Reactants Moles oi Reactants Recovered in Reaction Run No Mole Ratio I t 1?) 0434s I ggg NHiCl 0.114s on o NH4C1 0.114s. omo NH4C1 stable hydroxyl or amino groups are reacted at temperatures below about 85 degrees centigrade for periods of time up to three hours, three prodnets are obtained; to wit: primary amine, secondary amine and. sub-resinous bodies having some of the characteristics of a tertiary amine. The proportion of each of these products in the final product can be controlled by controlling the mole ratio of the reactants. For example, employing formalin, ammonium chloride and thiophene the proportions of primary amine, secondary amine and sub-resinous body may be controlled as shown in Table I. The results tabu-' lated in Table I were obtained by heating the reaction mixture at about 70 to about 80 degrees centigrade for about 1.5 hours. unreacted thiophene was removed, a diluent added to the residual liquid, ammonium chloride crystals removed, diluent removed, residual liquid neutralized with strongcaustic in the presence of benzene, the neutralized liquidextracted three times with benzene, the benzene stripped off and the residue distilled in a vacuum The fraction boiling between 19Q-205 degreescentigrade (cor-- rected to 760 millimeters of mercury) was considered to be primary amine, that boiling at 250-291 degrees centigrade (corrected v to 760 millimeters of mercury) was considered to be secondary amine and the residue was the sub- Thereafter the The variation of the molar ratio causes a variation in the molecular weight of the sub-resinous body as well as the proportion of sub-resinous body to the primary and secondary amines in the reaction product. The variation in molecular weight of the sub-resinous body with the variation in molar ratio of original reactants is demonstrated by the data in Table III.

(Those skilled in the art know that molecular weight determinations of this magnitude are subject to an experimental error of about :10 percent.) Thus, when formaldehydeis used in excess of the proportion 1:1:1 the molecula r weight of the subresinous body is increased} The sub-resinous body or amines are insoluble in alcohol, ether, chloroform and mineral oil'and soluble in benzeneand dioxane. fThe sub-resinous amines are viscous, light red to brown oils having anodor of amines.

resinous body. Although it, has, been demonstrated hat vari- TABLE I Moles 0i Rcactants. Yield 2:3333 of l.

Mole N0 ratio s coils 3??? NHlGl Amine I Amme resinous 2 Body 5 1o 5 j 1211 17.0 5.3 77.0 2 2 2 1=1=1 15.0 3.1 80.0 4 2 2 .21111 17.7 20.3 02.0 5 4 4 1.25:1:1 22.2 22.2 77.7 1 1 a 1=1=3 36.8, 15.2 48.0

The foregoing data show that the amount of sub-resinous bodies in the reaction product can be kept at a minimum by using an excess of thiophene and/or ammonium halide. Further more, that the. amount of primary amine produced is substantially constant unless an excess ation in the molar ratio of the thiophene and formaldehyde does not cause any appreciable variation in the proportion of primary amine in the product unless an excess of ammonium halide is used, it hasbeen found that the yield of primary amine and secondary amine can be i limeters of mercury) (secondary amine).

8-1 hard-resinous products are: obtained.- It is also to be noted thatexposure of filmsof. these-subresinous amines to the air over a period; of time produces a resinous hard film. I

TABLE V Moles of Reactants Sub-resinous Amines Example'No" A cgriaellllis P t P 1; OH M 1' ul (11180 15 ercen ercen 0 80 at 041348 011,0 M1401 No. Weight 1 1 0.5 59v 20.2 5.65 285 725 1 a 1 91 22. 9 e. 21 199 620 1 4 2 111 20.6 7.3 475 1 4 1 132 21. 2 s. s 370 651 is two or more moles for each mole of thiophene and each two moles of formaldehyde, the yieldof primary and secondary amines is increased These analyses lead to the postulation that these sub-resinous amines may be represented by the empirical formula (C4HnS-(CH2)2N)4Qm while theyield of sub-resinous amines is reduced. 20 where .Q is the moiety reacting in the A. S. T. M.

This is demonstrated in Table IV.

determination of hydroxyl number, nv equals zero TABLE IV Yield as er cent V Moles of Reactants I of theorgtical Mole Moles of Example No. Ratio Thlophene V Aqueous Utilized 1 G4H4S- CEZO NH4C1 I Amine I Amine II 'liormaldehyde provided by hexamethylenetetramine; 2 moles; of aqueous hydrochloric acid added.

In; order to obtain the data. presented in Table IV the reactants were mixed, brought to a reflux at about 7075 degrees centigrade and allowed to reflux for about one hour. The excess thiophene was removed by steam distillation. The residual oil was then'fractionated in vacuo to obtain one cut.boiling at 190-205 degrees centi grade (corrected to 760 millimeters of mercury) (primary amine) and a secondfraction boiling at 250-291 degrees centigrade (corrected to 760 mil- The yields were then calculated on the basis that the original amount of thiophene less the thiophene recovered as such is equal to the amount of thiophene which reacted. The per cent yield of each amine was then calculated on the amount of thiophene which reacted.

While the proportion of sub-resinous body. can

be kept at a minimum byreacting an amount of thiophene or ammonium halide in excess of that required for the molar ratio 1:1:1, the total yield and amount of sub-resinous amines canbe increased by increasing the molecular proportion of formaldehyde. This relation is demonstrated in Table V, the data for which were obtained by mixing the reactants in the molecular proportions shown and refluxing the reaction mixture for three hours. The reaction mixture was then neutralized and extracted with benzene. The yield of primary and secondary amines was very low. No formation of resinous products was observed. The crude sub-resinous amines were analyzed for sulfur, nitrogen and hydroxylgroup and the molecular weight determined. It is. to be noted: that aqueous formaldehyde was used. When aqueous formaldehyde is replaced by paraformaldehyde inthese proportions only resinous materials are obtained. However; when the subresinous products listed in Table V are heated,

to 3 and m is 4 to 5. The. calculated values-for sulfur and nitrogen, the hydroxyl number and. molecular. weight based; on this formula arev Bercentsulfuru 19.2. Percent nitrogen 8.49 HydroxylNo 340 Molecular weight 668. These values are to be compared with the observed values for-the sub-resinous amines produced in Example XXII. The following formulamay-be said to represent the sub-resinous prodnot obtained in Example XX:

[(C4H1'1S) 3 (CH2) 9N2(O H) 21 where n equals'zero to 3.

Calculated for Monomer Found" Percent Sulfur. Percent Nitrogen Hydroxyl No Molecular Weight than the unstable hydroxyl and amino groupsare attached to the thiophene nucleus likewise react with formaldehyde and ammonium chloride to produce alkylthenyl amines. For example, when Z-amylthiophene is condensed with formaldehydeand ammonium chloride, a product is obtained which has a sulfur content of 19.3 per cent and nitrogen content of 2.85 percent. This correspondswithin experimental error with the sulfur content of 18.65 per cent and the. nitrogen content of. 2.72'per cent of the tertiary amine represented by the formula (CH10C4H2SC'H2)3N.

.Thiophene is distinguished from benzene in at least one characteristic. Thiophene will react to a limited extent with the less reactive secondary amine hydrohalidesand formaldehyde whereas benzene or its more reactive homologues will not react with primary or secondary-amines nor with the more reactive ammonium halides. For ex ample, when one mole each of thiophene, formal-- 10 dark brown oily liquid remained. Distillation in vacuo gave: 9.0 grams of 2-thenyl amine (I), B. P. 55-65 degrees centigrade at 5 millimeters of mercury (190-203 degrees centigrade at 760 millimeters), 12 1.5650; 8.0 grams of di- -(2"-thenyl) amine (II) BQP. 115-145Ydegrees centigrade at 7 millimeters (250-291 degrees Centigrade at 76.0

millimeters) 11. 1.5914; grams of residue of unknown constitution.

AnaZysis.Calculate d for C5H'1SN. (I) v Nitro gen, 12.38 per cent; sulfur, 28.35 per cent. Found:

Nitrogen, 12.1 per cent; sulfur, 27.1 per cent. Calculated for CwHnSzN (II) Nitrogen, 6.7 per cent.

TABLE VI Percent Percent S B. P. i C.at'3

' Calc. Found Qa1c. Found 2-Theny] stearamide Z-Thenyl benzamide .1 2-Thenyl acetamide 2 Thenylaminebenzaldehyde 2-Tl1e'ny1urea sym. Di-(Z-thenyl) urea 2-Thenyl phthalimide Dl-(2-thenyl) phthalamida.

1 All melting points (uncorn). Block method.

amounts only, of the order of 1 to 2 per cent, of an amine were obtained.

The thenyl amines which are obtained by this method may be used as dye intermediates, antioxidants in lubricating oils, as insecticides, in the pharmaceutical industry as intermediates, and as intermediates in the production of other valuable materials.

The production of the thenyl amines and amines of thiophene derivatives is illustrated by the following non-limiting examples.

Example I A mixture of 56 grams (1.03 moles) of ammonium chloride, 168 grams (2 moles) of thiophene and 100 grams (1.23 moles) of 37 per cent aqueous formaldehyde were heated for three hours at 74 degrees centigrade. One hundred and fifteen grams of unreacted thiophene were recovered by decantation. To the resulting reaction product, a thick red syrup, ethyl alcohol was added. The mixture was filtered to remove the unreacted ammonium chloride. (This step need not beincluded in the process when the amine III is desired since the amount of ammonium chloride used in the reaction canbe controlled making recovery unnecessary.) Ethyl'alcohol was evaporated off on a steam bath and the thick red syrup neutralized with strong potassium hydroxide solution in presence of benzene. Three extractions with benzene from a saturated salt solution were necessary to remove the liberated amines. Benzene was stripped oif and 42.0 grams of a Example II To a mixtureof 168 grams (2 moles) of thiophene and 70 grams (0.5'mole) of hexamethylenetetramine equivalent to 2.5- moles of formaldehyde, 200 grams (2.0 moles) of aqueous hy drochloric acid-was dropped into the reaction vessel during a period of forty minutes. Thereaction mixture was kept for one hour at 76-80 degrees centigrade- Twenty-five grams of thiophene were recovered by distillation. The reaction mixture was diluted with alcohol and filtered to remove the ammonium chloride. The alcohol was evaporated ofif and the concentrate treated with grams of sodium hydroxide in 200 grams of water. The liberated aminev was extracted with benzene. The benzene was stripped ofi and distillation of the amine in vacuo gave: 33.0 grams of 2-thenyl amine (DJ, E. P. 192-205 dcgrees centigrade at 760 millimeters. Sixteen gramsof di-(Z -thenyl) amine (II), B. P. 260-280 degrees centigrade at 760 millimeters and,.1 00 grams of residue.

Phenyfl thiourea derivative or I. three recrystallizations from alcohol, M. P. 122-1225 de-. gree centigrade (uncorrected).

Example III aldehyde and 54.0 grams. (1.0 mole) '-,o f.:am-.

monium chloride :were-heated for 1 /2 hours at. refluxtemperature. No reaction took place.

Example IV A mixture of 252 .grams (3.0 moles) of thiophene, 60 .grams (2.0 moles) of paraforma'ldehyde, 108.0 grams (2:0 .moles) of ammonium chloride and 20 grams of acetic acid were heated for three hours at'78 degrees centigrade. The procedure from here on is the .same as in Example I. Yield of crude amine 112 grams. The nitrogen analysis, of these crude amines gave 6.5 per cent. Distillation in'vacuogave 17 grams of (I), 7 grams'of (H),'-and-84 grams of residue.

Analysis-Calculated for CmI-IuSzN (II): Ni-

trogen, 6.7 per cent. Found: Nitrogen, 6.98 per cent. Residue, found: Nitrogen, 5.8 per cent; sulfur, 28.3 per cent.

Example V The benzene soluble material was water washed I two timesand benzene stripped off. Yield 1.56 grams.

Example VI .A mixture of 168 grams (2 moles) :of thiophene, 120'grams (4 moles) 'ofparaformaldehyde, 108 grams (2 moles) of ammonium chloride and 20 grams of acetic acid were heated for 1% hours at 74 degrees centigrade. The reaction product was treated with a saturated aqueous solution of 2.00.grams of crystallinesodium acetate and Y300 milliliters .of benzene as in Example V. The precipitated benzene-insolubleamine was treated with caustic solution and the free amine was dissolved in benzene. Benzene wasstr-ipped off :and the amine had the following analysis:

Sulfur, 23.1 per cent; nitrogen, 4.67 ,per cent; hydroxyl No. .257 molecular weight, 1123.

The other ,portion, benzene-soluble amine,

when analyzed gave: Sulfur, 23.85 per cent; nitrogen, 4.68 per cent; dchlorine, 1.7 per cent.

Example VI I residue boiling 265 degrees at 760 millimeters.

Analysis.-Found-: Sulfur, 19.3 percent; nitrogen, 2-.85 per cent.

Example VIII A mixture of 331 grams (3.94 moles) of thiophene, 60 grams (2 moles) of-paraformaldehyde, 54 grams of ammonium chloride-and. 20 grams of acetic acid were heated for three hours at 77 degrees centigrade. Two hundred and :fortythree grams of thiophene-were recovered by dis-.

tillation. The reaction product .wasthen treated with sodium hydroxide (50 grams in '10'0'grams of water). in the presence .of benzene. The liberated amine was extracted with benzene from the saturated salt solution. The benzene was stripped off on afive-plate laboratory; glass column. Yield of crude amine was 129 grams. The theoretical yield is 130 grams assuming that 88 grams of thiophene had reacted. Distillation in vacuo gave: 113.4 gramsof 2-thenyl amine (I), (10.3 per cent of theoretical); 10-9grams of residue (84.0 per cent of theoretical), and 6.6 grams loss.

Example IX W A well'stirred-mixture of one *mole (84 grams) of thiophene, one mole (81 grams) of aqueous 3-7 per cent formalin solution, and 3 moles of ammonium chloride were brought to a reflux of 72 degrees centigrade. In 15 minutes a'yellow coloration began to take place. The reaction mixture was allowed to refluxonehour and then cubic centimeters of water were added. The condenser was arranged for downward distillation and the excess thiophene was steam distilled ofi. In this manner '53 grams 'of thiophene was recovered and 33 grams (0.37 mole) of thiophene entered into the reaction. Rectification of the mixture by standard procedures gave 17.5 grams of 2-theny1 amine and 7.0 grams of di-(Z-thenyl) amine as Well as 23.0 grams of residue. This corresponds to a 42 per cent yield of 2-theny1 amine and an 18.3 per cent yield of di-(2-thenyl) amine.

Example X To 49 grams (0.6 mole) of thiophene and 48 grams (0.6 mole) of aqueous formalin (36 per cent) were added 115 grams (1.2 moles) of ammonium bromide. The procedure here was the same as in previous examples. 9 grams of 2'- thenyl amine (I), 6 grams of di-(Z-thenyl) amine (II), and lfi-grams of residue (III) was obtained.

Example XI A mixture of 42 0 grams (50 moles) of -thio p'hene; BOO-grams (10 moles) of'trioxymethylene, 270 grams (5.0 moles) of ammonium chloride and 50 grams of acetic acid were "refluxed for 30 minutes. A heat of reaction began and the temperature was maintained between 74-84 degrees centigrade by means of an ice bath. The reaction mixture was stirred for an additional hour during which time the temperature dropped to 46 degrees centigrade. To the reaction mixture was then added 500 cubic centimeters of per cent alcohol and filteredto remove the precipitated ammonium chloride. The alcohol was evaporated and the 991 grams of concentrate were treated with 6 moles of sodium hydroxide.

in a 40 per centsolution, in thepresence of hen The liberated amine was thus extracted zene. with benzene. The benzene was topped oh and distillation of the amine in'vacuo gave 81.5 grams of '2 -theny1 amine (I), 365 grams of di-(2- thenyl) amine (II) and 413.5 grams of residue. v

The yieldsof I and II are 14 per cent and .7 .per cent of theoretical, respectively.

Emma XII 10 grams of acetic acid were reacted at the :de-.

sired temperature, 74-84 degrees centigrade for 1 hours, 28 grams of thiophene were recovered.

The refining procedure was the same as. that in Example XI; The topped reaction product weighed 128.5 grams. Distillation of the free amine in vacuo gave 20 grams of 2-thenyl amine Example XIII A vigorously stirred mixture of 336 grams" (4.0 moles) of thiophene, 60 grams (2.0 moles) of trioxymethylene, 108 grams (2.0 moles) of ammonium chloride and 20 grams of acetic acid were heated at 74-84 degrees centigrade for 1% hours."

The refining procedure was the same as in Example XI. Two hundreds and seventeen grams of thiophene and 63 grams of ammonium chloride were recovered.

Distillation of the liberated amine in vacuo gave 20.0grams of 2-thenyl amine (I), 23.0 grams of di-(Z-thenyl) amine and 77.0 grams of residue.

The yields of (I) and (II) are 13 per cent and 16 per cent'of theoretical, respectively.

From the foregoing it will be recognized'that thiophene and its alkyl derivatives react with aqueous formaldehyde and ammonium halides much more easily than with primary or secondary amine hydrohalides. It will also be evident" that when polymerized forms of formaldehyde are used a smallamount of acid such as acetic acid or, in general, in acid having a dissociation constant of 10' or'less or any agent capable of depolymerizing'the formaldehyde poymer, suchas water, must be used. Furthermore, when hexamethylenetetramine is used, hydrochloric acid or one of the other hydrogen halides HBr or HI must be used. Accordingly, those skilled in the art will recognize that the production of high yields of primary and secondary thenyl amines I involves reacting thiophene or its derivatives as defined hereinbefore'witn'formaldehyde in the presence of at leastZ moles of ammonium chloride for each'mole of thiophene at temperatures of 65 degrees centigrade to'refiux temperature of about 85 centigrade for up to three hours, and

preferably for about 1.5 to about 3 hours at the aforesaid reflux temperature.- Aqueous iormalde-.

hyde can be replaced by its polymers or hexamethylenetetramine. mers of formaldehyde are used, sufficient acid must be present to depolymerize the polymerand when hexamethylenetetramine is used, hydrorosion of bearings as indicated by the bubble test. As those skilled in the art know, the bubble test is described in many United States patents, for' example, U. S. Patent'No. 2,361,353. v a

The base or blank oil used inthese tests was Pennsylvania solvent-refined oil of 53 seconds Saybolt Universal viscosity at 210 degrees Fahrenheit. The data present in Table VII show that both the primary and the secondary thenyl amines are efiective inhibitors at concentrations as low as 0.06 per cent (1 of 1 per cent) by weight. Each test was carried out for 22 hours at 175 degrees centigrade.

However, when the poly- I TABLE VII Milligrams loss in weight Blank Oil 20, 20.20.24; averageszlfn Percent Mg. loss in additive weight 4 Compound: 7 2-Thenyl amine T 1 0' $4 0 l/ 1 D m 1M6 i- 2- eny amine I y it: 0 V4 l is 1 516 0 142 t 15 While non resinous primary and-secondary thenyl amines together with sub-resinousnitrogenous materials of the nature of tertiary amines are produced by heating thiophene or derivatives thereof with formaldehyde or polymers thereof and ammonium halide (less readilywith primary and secondary amines) for upto 3 hours at 75-80, degrees centigrade, essentially thermoplasticnitrogenous resins can be produced by heating thiophene and :its derivatives having stable electropositive substituents attached to the nucleus with formaldehyde or its polymers and ammonium halidesother than the fluoride v for .3 hours at temperatures of 75.85 degrees Fahrenheit, or at the reflux temperature. Thus,.

whenthiopene or alkyl thiopenes are heated for 3 hours with vformaldehyde and .ammonium halide or hexamethylenetetramine and hydro-. chloricacidor .paraformaldehyde Or trioxane,z

and acetic acid, the resins obtained by neutralizing the water solution are yellow to brown, thermoplastic, water-soluble resins. i

Essentially: the same end-products are produced whether aqueous formaldehyde in the form of formalin (37-per cent aqueou formaldehyde), paraformaldehyde, or trioxane be used in this reaction. Hexamethylenetetramine and hydrogen halide acid can be substiuted for formaldehyde and ammonium halide to produce essentially the same end-products.

The production of these nitrogenous type resins is. illustrated by the following non-limiting examples. v

7 Example XIV A mixture of l68'grarns (2 moles) of thiophene, 1 107 grams (2 moles) of ammonium chloride and 200' grams (2.5-mo1es) of 3'7 per cent aqueous formaldehyde wereheated for six hours at 72 degrees 'centigrade. One hundred and thirteen rams (67.4 per cent) of thiopene had reacted. The resulting product, a thick, red syrup was dissolved in ethyl alcohol and filtered. Ethyl alcohol was removed by evaporation on a steam bath followed by neutralization with potassium hydroxide solution. A brown resinous material precipitated out. The yield was grams The calculated yield was 169 grams. I

Analysis.Sulfur, 24.9 per cent; nitrogen 6.98

per cent.

Example XV To 93 grams (1 mole) of aniline cooled in ice,

mole) of aqueous formaldehyde were added and 4 dried in vacuum dessicator. The yield was 145 grams (calculated yield 172 grams).

AndZysis.Sulfur, 1.03 per cent; nitrogen, 10.4 per cent.

. Example XVI To'a mixture of 31 grams (0.5 mole) of urea, 41 grams (0.5 mole) of formalin and 42 grams (0.5 mole) of thiopene, 50 grams (0.5 mole) of concentrated hydrochloric acid was added slowly while the mixture was cooled. A white solid precipitate formed immediately. After heating for six hours at reflux temperature only a trace of thio'pene could be detected. The reaction mixture was filtered and the solid was washed withxwater, thenv with dilute caustic solution followed with two water washes. The resinous materialwas' dried forlz'hours in asteam oven. The yield of resin as the hydrochloride salt was 93 grams.

A.1 zaZ' sis.Sulfur, 14.2 per cent; nitrogen, 2(k6lper cent; chlorine, 5.36 per cent.

' Example-XVII illustrates the useof alkyland aryljpolyamines.

' Example XVII To 30 grams (0.5 mole) ofethylene diamine cooled in an ice b'ath,i200 grams (2.0 moles) of concentrated hydrochloric acid Were-added. To

the'hydrochloride salt thus formed, .84 grams (1 mole) fof thiopene and 81 grams (1 mole) of aqueormlformaldehydewere added. The reaction mixture was stirred .and heated for two hours at 75 degrees centigrade. The resulting reaction mixture was filtered and washed with alcohol. The solvent and unreacted thiopene were stripped oil under vacuum. The yield of resinous material was 139 grams.

Analysis-Found: .Sulfur, 19.0 per cent; nitrogen, 5.98 perzcent.

' Eazample XVIIl Eighty-four grams (1 mole) of thiophene, 90 grams (1 mole) of paraformaldehyde (equivalent to 3 molesof formaldehyde), 54 grams (1 mole) of ammonium chloride and grams of acetic acid were mixed together in a 500 milliliter 3- necked, flask fitted with a mechanical stirrer,

thermometer, and reflux condenser and heated to 75 degrees .centigrade. Within afew minutes yellow to .red coloration started anda vigorous heat of reaction set in necessitating ice bath cooling. After 15 minutes the heat of reaction subsided and the mixture was heated at 80-.-85 degrees -centigrade forz hours thereafter. The materialwas cooled, transferred to a beaker, and

neutralized with lO'per cent sodium hydroxide solution. A solid yellow to brown resinous mass precipitated. This was water washed on'a rubber mill and the followinganalyses obtained:

Per cent'sulfur "21.5 Per cent nitrogen 6.09 Per cent residual chlorine 0.31

Per cent ash 1.0

Example'XIX Example IV-was repeatedusing 1 mole of thio.

A resinous product separated out which was washed with water and to,4 moles of formaldehyde), 1 mole-of ammo;

nium chlorideandZO grams of acetic acid The following analyses were obtained 'on the resinous product Per cent sulfur "204 Per cent nitrogen "5.78

Per cent residual chlorine .1100.

Per cent ash. 0.3

Example XX Example IV was repeatedusing 1 mole of thiophene, 1.3 moles of trioxymethylene (equivalent to '4 moles of formaldehyde) ',.2 moles of .a'fnmonium chloride and-20 gram'sof acetic acid. The resin obtained was much. more brittle than those of Examples VIII and XIX-and appearedto have a molecular weight much higher than previous resins. I

It will be seen from tlie'foregoing that trioxy- ,methylene is the preferred form of formaldehyde the formation of the desired resins be considered as sub-resinous;-intermediatesi In 1948 U. s. Patents Nos. 2,453,08l5 and 2,453,086 were granted to Philip Caesar and, Alexander N. Sachanenandto Philip D. Caesar. respectively. These patents; disclose the prepara-.

tion of thiophene-aldehyde-and alkyl thiophene aldehyde resins employing well-known acidic condensing agents.- Non-limiting examples'of these acid condensing agentsare sulfuric acid, bydrochloric acid, maleic acid,fphosphoric acid,-a nd anhydrous hydrofluoric acid as well as ammoandammonium sulfate.

nium chloride, zinc chloride, mercuric chloride,

While it would seem that the resins prepared described in the Caesarpatents might'be similar to those of the presentinventiomit is to benQtedthat the Caesar resin'siwill .onlylbe nitrogenous when the condensingagent'is ammonium chloride. 'Ori'the other hand, when thiophene, formaldehyde "and ammonium"'chloride are mixedin' the molecular ratio "of 1:1-':1 andheated ina sealed tube for 5-10 hours at 100 C, .a resinlis obtained which in the hydrohalide form is water. the three reactants. are

insoluble whereas when heated to not more than reflux temperature, i. e., about drohalide form is soluble in water. Resins which are water-insoluble in the hydrohal'i'clefform .are

also obtained when aniline, urea, ethylene diamine, and the like as hydroha'lidjes'are reacted at reflux temperatures with thiophene .andformaldehyde resins are obtained which in the hydro halide form are insoluble in water.

Oneimportant used the resins of the presentinvention is dependent upon this characteristic of solubility in water'when inthe form of hydrohalides. In the coatin'g 'or impregnating of textile fibers inthe pastithas been'customaryto employ resinous materials in solution in nonaqueous solvents generally of flammable nature.- With :the advent of these novel resins which'in the hydrohalide form are water-soluble it is now possible to impregnate textile fabrics with these novel water-soluble nitrogenous'resins from'an" aqueous bath and treat the textile 'flber impreg C. a resin is obtained-whichrinthe hy nated with the hydrohalide form of the resin with a strong base such as caustic soda to free the amine base. In this way the use of non-aqueous, flammable solvents and the concomitant hazards are avoided. I

The nitrogenous type resins described herein which in the hydrohalide form are soluble in water can be used in the common manner for which prior art thermoplastic resins have been employed. For example, they may be used to make textile fibers water-repellant as disclosed in copending application for U. S. Patent Serial No. 763,744, filed July 25, 1947, in the names of John W. Schick, Howard D Hartough and Darwin E. Badertscher, now Patent 2,559,260, issued July 3, 1951. They may be used in conjunction with salts of copper, mercury and the like to provide-waterrepellant, mildew-proofed textile fabrics as disclosed in co-pending application Serial No. 763,743 filed July 25, 1947, in the names of Paul V. Keyser, John S. Schick and Howard D. Hartough. now Patent 2,582,870, issued January 15, 1952.

The present application is a continuation-inpart of our copending application Serial No. 636,511, filed December 21, 1945, and now abandoned,

We claim:

1. The method for producing nitrogenous condensation products having as a characterizing group the thiophene residue, C iHns, wherein n equals zero to 3, which comprises condensingat temperatures of about 65 C. to about 85 C. a thiophene compound selected from'the group consisting of thiophene, an alkyl thiophene, and a halo thiophene, formaldehyde, and an ammonium halide selected from the group consisting of ammonium chloride and ammonium bromide, the reactants bein present in the reaction mixing a hydrohalide salt of a basic nitrogenous condensation product, mixing said reaction mixture with an aqueous alkaline solution to decompose said hydrohalide salt and to set free said basic nitrogenous condensation product, and recovering the freed basic nitrogenous condensation product.

3. The method for producing nitrogenous condensation products having as a characterizing group the thiophene residue, C4HnS, wherein n equals zero to 3, which comprises condensing at obtain a reaction mixture containing a hydroture in the molar proportions of thiophene compound formaldehyde ammonium halide, of l to 5:03 to 4:025 to 4, to obtain a reaction mixture containing a, hydrohalide salt of a basic nitrogenous condensation product, mixing said reaction mixture with an aqueous alkaline solution to decompose said hydrohalide salt and to set free said basic nitrogenous condensation product, and recovering the freed basic nitrogenous condensation product.

2. The method for producing-nitrogenous condensation products having as a characterizing group the thiophene residue, C4H1Ls, wherein n equals zero to 3, which comprises condensing at temperatures of about 65 .C. to about 85 C. a thiophene compound selected from the group consisting of thiophene, an alkyl thiophene, and a halo thiophene, a reversible polymer of formaldehyde, and an ammonium halide selected from the group consisting of ammonium chloride and ammonium bromide, in the presence of an acid having a dissociation constant not greater than about 10 the reactants being present in the reaction mixture in the molar proportions of thiophene compound reversible polymer of formaldehyde ammonium halide, of l to 5:0.3 to 410.25 to 4, to obtain a reaction mixture containhalide salt of a basic nitrogenous condensation product, mixing said reaction mixture with an aqueous alkaline solution to decompose said hydrohalide salt and to set free said basic nitrogenous condensation product, and recovering the freed basic nitrogenous condensation product.

4. A nitrogenous condensation product being Water-soluble in the hydrohalide form, produced by the process set forth in claim 1.

5-. A nitrogenous condensation product being water-soluble in the hydrohalide form, produced by the process set forth in claim 2.

6. Di-(Z-thenyl) amine, (C4H3SCH2)2 NH.

HOWARD D. HARTOUGH. SIGMUND'J. LUKASIEWICZ. REFERENCES orrEn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,114,121 Bender Apr. 12,1938 2,453,085 Caesar Nov. 2, 1948 2,453,086 Caesar Nov. 2, 1948 v FOREIGN PATENTS Number Country Date 51,629 Holland Dec. 15, 1941 109,201 Australia Apr. 11, 1942 OTHER REFERENCES Ser. No. 314,449, Zerweck (A.P.C.), published April 20, 1943.

Blicke: Jour. Amer. Chem. Soc., vol. 64, pages 477-480 (1942).

Hartough: Jour. Amer. Chem. Soc., vol. 68, pages 13891390, July 1946.

Hartough: Jour. Amer. Chem. Soc., vol. 70, pages 1146-1149 (1948).

I-Iartough: Jour. Amer. Chem. Soc., vol. 70, pages 4013-4017, December 1948. 

1. THE METHOD FOR PRODUCING NITROGENEOUS CONDENSATION PRODUCTS HAVING AS A CHARACTERIZING GROUP THE THIOPHENE RESIDUE, C4HNS, WHEREIN N EQUALS ZERO TO 3, WHICH COMPRISES CONDENSING AT TEMPERATUES OF ABOUT 65* C. TO ABOUT 85* C. A THIOPHENE COMPOUND SELECTED FROM THE GROUP CONSISTING OF THIPHENE, AN ALKYL THIPHENEN, AND A HALO THIOPHENE, FORMALDEHYDE, AND AN AMMONIUM HALIDE SELECTED FROM THE GROUP CONSISTING OF AMMONIUM CHLORIDE AND AMMONIUM BROMIDE, THE REACTANTS BEING PRESENT IN THE REACTION MIXTURE IN THE MOLAR PROPORTIONS OF THIOPHENE COMPOUND : FORMALDEHYDE : AMMONIUM HALIDE, OF 1 TO 5:0.3 TO 4:0.25 TO 4, TO OBTAIN A REACTION MIXTURE CONTAINING A HYDROHALIDE SALT OF A BASIC NITROGENOUS CONDENSATION PRODUCT, MIXING SAID REACTION MIXTURE WITH AN AQUEOUS ALKALINE SOLUTION TO DECOMPOSE SAID HYDROHALIDE SALT AND TO SET FREE SAID BASIC NITROGENEOUS CONDENSATION PRODUCT, AND RECOVERING THE FEED BASIC NITROGENEOUS CONDENSATION PRODUCT. 